A malnourished baby at a hospital in north-east Nigeria.
Photograph: Afolabi Sotunde/Reuters

A preventable, human-manufactured disaster appears to be unfolding in north-east Nigeria. While the spotlight of media attention is facing elsewhere, the spectre of starvation stalks an area staked out by jihadists as their caliphate. One small state in Nigeria has more displaced people than the entire refugee influx that arrived in Europe last year. The brutal armed conflict has sent a million children out of school. Health services have been decimated and cholera and polio, once eradicated, have returned. The violence of Boko Haram, the jihadist group that still controls parts of the region, is characterised by child killing, abductions and sexual abuse – an oppressive, murderous atmosphere hardly conducive to stable government in a part of Africa the size of Belgium.

Farmers are unable to harvest their crops and aid agencies say they are unable to reach isolated communities. The region is now entering its third season without a harvest. Where food is available, prices have soared – partly due to a decision to depreciate Nigeria’s currency, the naira.

There are clear warning signs that a famine looms while the international community stands by, watches and waits. The concern is that the world springs into action after it is too late. It’s what happened in Somalia six years ago when a quarter of a million people, half of whom were children under five, died.

Now Save the Children is warning that there is a “real and immediate” threat to the lives of 400,000 children who are malnourished and starving. The charity rightly says the crisis is being crowded out of the humanitarian agenda by the more highly visible disasters affecting Syria, Iraq and Yemen. There are concrete steps the world can take. On Monday the United Nations will convene its yearly attempt to assess needs, decide response strategies, and present plans to donors for the areas of greatest global need.

Nigeria cannot excuse itself as a failed state. It is Africa’s second-biggest economy. However, more imaginative ways of helping the country are also needed. Save the Children suggests turning ill-gotten gains into crisis-denying cash. Since September illicit Nigerian cash laundered through Britain and seized by British police can be returned to Africa to help with development projects.

The sums are not small: recently a former Nigerian state governor pleaded guilty to a £50m fraud. In 2001, it emerged that a former Nigerian dictator laundered $1.3bn through London banks. Nigeria ranks 136 out of 167 in Transparency International’s corruption index. Its current president asked Britain to return assets held by dishonest Nigerians, shrugging off David Cameron’s suggestion that his nation was “fantastically corrupt”.

British aid needs to be spent wisely and we need sanctions, not rewards, for City institutions that aid capital flight. The proposal is a good way of returning money stolen from Africa’s poorest – and filling the gap between rhetoric and reality in the financing of humanitarian assistance.